02 deville rough idiling

Check the coils, there may be a bad coil. That lets moisture in it, and causes the engine to mis fire. God-Bless! Its worth a try!

run the fault codes to ensure that the EGR valve is faulty. Engine lights to not always come on unless there is something drastic going on with the engine /gearbox so that you can stop the car before damage is done.

there is a tps located on the intake where the inlet tube for air intake connects, it would be on the left side of the throttle body. does the trk run rough on idle? up/down sputter sometimes stall? Is check engine light on? if no light,check all vacuum lines for cracks/splits loose fit. do this by spraying carb choke cleaner on connections motor rpms will change if leak is present. also spray around perimeter of intake housing where mates with lower intake if engine revs you have bad intake gasket.I Just replaced upper and lower intake on my 98 and shazaam, runs like it should. but do your checks first,unessasary fixes are costly and **** you off.

there is no such thing free, if you need info just post then some one may be able to help you

Go to any auto parts store and get two bottles of a fuel additive called seafoam. Pour one bottle in when you refill your tank the next two times. problem solved.

put a socket on the middle bolt of idiler pull and either tighten/orloosen will move the idiler pulley out of the way. then have another ratchet ready to get your other bolt off... might be easier to just take out that bolt on idiler pull and that will remove the pulley to?? your choice ! Richie

GO TO AUTOZONE OR YOUR LOCAL DEALER AND HAVE THEM PLUG IN THE DIAGNOSTIC MACHINE. IF THERE IS NOTHING WRONG HAVE THEM RESET IT. AUTOZONE WILL DO IT FOR FREE. DEALERS WONT

major service

NEED TO CHECK YOUR IGNITION COILS JUST REPLACED MINE AND RUNS GREAT

ok this sounds easy when you ran the vehicle the computer controled the idiling motor now that you replace the idiling motor the computer hasnt been reset to except the new parameters
once you reset computer this should bring the idle back down to its specified idle
you can also adjust back of gas pedel the idle cable and on the throttle body by the idling screw